Revision: 4644
Author: [email protected]
Date: Wed May 12 02:00:29 2010
Log: ARM: Fix jumptargets to actually merge virtual frames.
Make use of the new functionality to make ++ and --
non-spilled operations.
Review URL: http://codereview.chromium.org/2041010
http://code.google.com/p/v8/source/detail?r=4644
Modified:
/branches/bleeding_edge/src/arm/codegen-arm.cc
/branches/bleeding_edge/src/arm/virtual-frame-arm.cc
/branches/bleeding_edge/src/arm/virtual-frame-arm.h
=======================================
--- /branches/bleeding_edge/src/arm/codegen-arm.cc Tue May 11 01:27:56 2010
+++ /branches/bleeding_edge/src/arm/codegen-arm.cc Wed May 12 02:00:29 2010
@@ -4958,7 +4958,6 @@
#ifdef DEBUG
int original_height = frame_->height();
#endif
- VirtualFrame::SpilledScope spilled_scope(frame_);
Comment cmnt(masm_, "[ CountOperation");
bool is_postfix = node->is_postfix();
@@ -4967,10 +4966,8 @@
Variable* var = node->expression()->AsVariableProxy()->AsVariable();
bool is_const = (var != NULL && var->mode() == Variable::CONST);
- // Postfix: Make room for the result.
if (is_postfix) {
- __ mov(r0, Operand(0));
- frame_->EmitPush(r0);
+ frame_->EmitPush(Operand(Smi::FromInt(0)));
}
// A constant reference is not saved to, so a constant reference is not a
@@ -4980,35 +4977,33 @@
// Spoof the virtual frame to have the expected height (one higher
// than on entry).
if (!is_postfix) {
- __ mov(r0, Operand(Smi::FromInt(0)));
- frame_->EmitPush(r0);
+ frame_->EmitPush(Operand(Smi::FromInt(0)));
}
ASSERT_EQ(original_height + 1, frame_->height());
return;
}
+ // This pushes 0, 1 or 2 words on the object to be used later when
updating
+ // the target. It also pushes the current value of the target.
target.GetValue();
- frame_->EmitPop(r0);
JumpTarget slow;
JumpTarget exit;
- // Load the value (1) into register r1.
- __ mov(r1, Operand(Smi::FromInt(1)));
-
// Check for smi operand.
- __ tst(r0, Operand(kSmiTagMask));
+ Register value = frame_->PopToRegister();
+ __ tst(value, Operand(kSmiTagMask));
slow.Branch(ne);
// Postfix: Store the old value as the result.
if (is_postfix) {
- __ str(r0, frame_->ElementAt(target.size()));
+ frame_->SetElementAt(value, target.size());
}
// Perform optimistic increment/decrement.
if (is_increment) {
- __ add(r0, r0, Operand(r1), SetCC);
+ __ add(value, value, Operand(Smi::FromInt(1)), SetCC);
} else {
- __ sub(r0, r0, Operand(r1), SetCC);
+ __ sub(value, value, Operand(Smi::FromInt(1)), SetCC);
}
// If the increment/decrement didn't overflow, we're done.
@@ -5016,41 +5011,50 @@
// Revert optimistic increment/decrement.
if (is_increment) {
- __ sub(r0, r0, Operand(r1));
+ __ sub(value, value, Operand(Smi::FromInt(1)));
} else {
- __ add(r0, r0, Operand(r1));
+ __ add(value, value, Operand(Smi::FromInt(1)));
}
- // Slow case: Convert to number.
+ // Slow case: Convert to number. At this point the
+ // value to be incremented is in the value register..
slow.Bind();
- {
- // Convert the operand to a number.
- frame_->EmitPush(r0);
+
+ // Convert the operand to a number.
+ frame_->EmitPush(value);
+
+ {
+ VirtualFrame::SpilledScope spilled(frame_);
frame_->InvokeBuiltin(Builtins::TO_NUMBER, CALL_JS, 1);
- }
- if (is_postfix) {
- // Postfix: store to result (on the stack).
- __ str(r0, frame_->ElementAt(target.size()));
- }
-
- // Compute the new value.
- __ mov(r1, Operand(Smi::FromInt(1)));
- frame_->EmitPush(r0);
- frame_->EmitPush(r1);
- if (is_increment) {
- frame_->CallRuntime(Runtime::kNumberAdd, 2);
- } else {
- frame_->CallRuntime(Runtime::kNumberSub, 2);
+
+ if (is_postfix) {
+ // Postfix: store to result (on the stack).
+ __ str(r0, frame_->ElementAt(target.size()));
+ }
+
+ // Compute the new value.
+ frame_->EmitPush(r0);
+ frame_->EmitPush(Operand(Smi::FromInt(1)));
+ if (is_increment) {
+ frame_->CallRuntime(Runtime::kNumberAdd, 2);
+ } else {
+ frame_->CallRuntime(Runtime::kNumberSub, 2);
+ }
}
+ __ Move(value, r0);
// Store the new value in the target if not const.
+ // At this point the answer is in the value register.
exit.Bind();
- frame_->EmitPush(r0);
+ frame_->EmitPush(value);
+ // Set the target with the result, leaving the result on
+ // top of the stack. Removes the target from the stack if
+ // it has a non-zero size.
if (!is_const) target.SetValue(NOT_CONST_INIT);
}
// Postfix: Discard the new value and use the old.
- if (is_postfix) frame_->EmitPop(r0);
+ if (is_postfix) frame_->Pop();
ASSERT_EQ(original_height + 1, frame_->height());
}
=======================================
--- /branches/bleeding_edge/src/arm/virtual-frame-arm.cc Mon May 10
06:23:42 2010
+++ /branches/bleeding_edge/src/arm/virtual-frame-arm.cc Wed May 12
02:00:29 2010
@@ -72,8 +72,15 @@
void VirtualFrame::MergeTo(VirtualFrame* expected) {
if (Equals(expected)) return;
+ MergeTOSTo(expected->top_of_stack_state_);
+ ASSERT(register_allocation_map_ == expected->register_allocation_map_);
+}
+
+
+void VirtualFrame::MergeTOSTo(
+ VirtualFrame::TopOfStack expected_top_of_stack_state) {
#define CASE_NUMBER(a, b) ((a) * TOS_STATES + (b))
- switch (CASE_NUMBER(top_of_stack_state_, expected->top_of_stack_state_))
{
+ switch (CASE_NUMBER(top_of_stack_state_, expected_top_of_stack_state)) {
case CASE_NUMBER(NO_TOS_REGISTERS, NO_TOS_REGISTERS):
break;
case CASE_NUMBER(NO_TOS_REGISTERS, R0_TOS):
@@ -154,7 +161,7 @@
UNREACHABLE();
#undef CASE_NUMBER
}
- ASSERT(register_allocation_map_ == expected->register_allocation_map_);
+ top_of_stack_state_ = expected_top_of_stack_state;
}
@@ -625,6 +632,40 @@
Register dest = kTopRegister[top_of_stack_state_];
__ Move(dest, reg);
}
+
+
+void VirtualFrame::SetElementAt(Register reg, int this_far_down) {
+ int virtual_elements = kVirtualElements[top_of_stack_state_];
+ if (this_far_down == 0) {
+ Pop();
+ Register dest = GetTOSRegister();
+ if (dest.is(reg)) {
+ // We already popped one item off the top of the stack. If the only
+ // free register is the one we were asked to push then we have been
+ // asked to push a register that was already in use, which cannot
+ // happen. It therefore folows that there are two free TOS
registers:
+ ASSERT(top_of_stack_state_ == NO_TOS_REGISTERS);
+ dest = dest.is(r0) ? r1 : r0;
+ }
+ __ mov(dest, reg);
+ EmitPush(dest);
+ } else if (this_far_down == 1) {
+ int virtual_elements = kVirtualElements[top_of_stack_state_];
+ if (virtual_elements < 2) {
+ __ str(reg, ElementAt(this_far_down));
+ } else {
+ ASSERT(virtual_elements == 2);
+ ASSERT(!reg.is(r0));
+ ASSERT(!reg.is(r1));
+ Register dest = kBottomRegister[top_of_stack_state_];
+ __ mov(dest, reg);
+ }
+ } else {
+ ASSERT(this_far_down >= 2);
+ ASSERT(virtual_elements <= 2);
+ __ str(reg, ElementAt(this_far_down));
+ }
+}
Register VirtualFrame::GetTOSRegister() {
=======================================
--- /branches/bleeding_edge/src/arm/virtual-frame-arm.h Mon May 10 04:32:25
2010
+++ /branches/bleeding_edge/src/arm/virtual-frame-arm.h Wed May 12 02:00:29
2010
@@ -229,8 +229,9 @@
// An element of the expression stack as an assembly operand.
MemOperand ElementAt(int index) {
- AssertIsSpilled();
- return MemOperand(sp, index * kPointerSize);
+ int adjusted_index = index - kVirtualElements[top_of_stack_state_];
+ ASSERT(adjusted_index >= 0);
+ return MemOperand(sp, adjusted_index * kPointerSize);
}
// A frame-allocated local as an assembly operand.
@@ -355,6 +356,12 @@
void EmitPush(MemOperand operand);
void EmitPushRoot(Heap::RootListIndex index);
+ // Overwrite the nth thing on the stack. If the nth position is in a
+ // register then this turns into a mov, otherwise an str. Afterwards
+ // you can still use the register even if it is a register that can be
+ // used for TOS (r0 or r1).
+ void SetElementAt(Register reg, int this_far_down);
+
// Get a register which is free and which must be immediately used to
// push on the top of the stack.
Register GetTOSRegister();
@@ -459,6 +466,10 @@
// onto the physical stack and made free.
void EnsureOneFreeTOSRegister();
+ // Emit instructions to get the top of stack state from where we are to
where
+ // we want to be.
+ void MergeTOSTo(TopOfStack expected_state);
+
inline bool Equals(VirtualFrame* other);
friend class JumpTarget;
--
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